Stand-up bags are used in a wide variety of applications. One common application is to hold food and other items that are purchased at retail establishments, such as department or grocery stores. Stand-up bags have also been applied to fast food establishments as a means for transporting the purchased food. The stand-up bags provide a relatively inexpensive way to deliver multiple items to a customer who can easily transport the items and secure them in a stable position on any countertop or similar surface.
A common type of stand-up bag is fabricated from a paper material. The paper may be coated, such as with a wax or a polymer, so as to resist liquid spills and grease absorption. Generally, liquid spills or other moisture application to a paper bag will destroy the integrity of the bag or the paper, causing the bag to fail and damage to the material inside the bag. Stand-up bags may also be fabricated from a polymer material so as to reduce the risk of bag failure, since most polymer materials are substantially resistant to moisture absorption.
There are a number of types of polymer bags. One form of polymer bags includes a sealing flange that extends from the bottom end of the bag, which may prevent the bag from standing upright. Polymer bags may also be formed in a manner similar to paper bags, including a number of folded layers at the bottom. In some bags, a separate patch is applied to cover the flange or folds to create a flat surface and to increase strength.
The addition of patches and the folding process typically results in additional process steps. In addition, the bottom surface of the bag includes multiple layers of material, which also adds to material costs. Thus, a manufacturing process eliminating or minimizing one or more of these drawbacks will serve to create a more economical product.